When the cactus is too large for its current pot, you will need to replace the pot if you want the plant to remain healthy. Moving a cactus can seem intimidating, but as long as you protect yourself from the thorns and prevent damage to the cactus roots, this replanting process should be a success. Here's how.
Step
Method 1 of 3: Removing the Old Potted Cactus
Step 1. Know when to replace the cactus pot
For most cactus species, you will need to replace the pot once the roots begin to show through the pot's drainage holes or after the cactus crown reaches the rim of the pot.
- This will usually happen every two to four years.
- Replace your cactus pots during the dry season, usually in late winter or early dry season. The roots may break during the process, and moisture can cause the damaged roots to rot.
Step 2. Put on gloves
Put your hands in thick leather gloves. The material should be thick so that it can help protect you from plant thorns.
Gloves alone may not be enough to protect your skin. However, if you are taking other protective measures, you should consider wearing thick gloves for protection
Step 3. Loosen the soil
Run a dull knife around the pot, and use a sawing motion to help separate the soil. Continue as necessary until the soil comes off as a solid mass.
- If you have a plastic pot, you can also try squeezing the sides of the pot to loosen the soil inside. Also press along the sides of the pot with a dull knife to help loosen the soil.
- The soil around the root mass should loosen completely before you remove the cactus. Otherwise, the cactus may be damaged.
Step 4. Lift the cactus with newspaper
Stack several sheets of newspaper and fold them in thirds to make a thick, sturdy wrapping cover. Wrap this sheet of newspaper around your cactus. Carefully pull the newspaper while holding the cactus as you do this, and lift the newspaper and cactus out of the pot.
Or, you can skip the newspaper and use a pair of old barbecue tongs to lift the cactus out. The idea is simply to keep your skin as far away from the cactus spines as possible
Method 2 of 3: Preparing the Cactus for a New Pot
Step 1. Clean the roots
Place the cactus in your workspace and use your fingers to remove a large piece of soil from the roots. Also separate the roots carefully.
- The roots don't need to be completely clean, but most of the soil should be removed.
- Keep your gloves on for this part of the process.
Step 2. Check the roots
Inspect the roots for signs of rot, disease, or pests. Handle and treat these problems as necessary when you find them.
- Apply a fungicide to get rid of rot or other fungus.
- Apply a mild pesticide to get rid of any pests.
- Use small scissors to cut off any roots that appear dry or dead.
Step 3. Consider pruning the roots
Root pruning is somewhat controversial, and your cactus will likely survive the replacement procedure even if you leave the roots alone. However, root pruning can help plants grow more efficiently, especially if done correctly.
- Large taproots take up very few nutrients. These roots transport and store nutrients, but don't really absorb much, so they don't help the cactus grow faster.
- Larger root cuttings can improve the health of the capillary roots, which are responsible for drawing water and nutrients into the plant.
- Use a sharp, clean knife to cut the primary taproot one-fifth to one-half its current size. Cut off the larger roots as well, shortening them by one-fifth to half their size.
Step 4. Let the roots dry
Store the cactus in a warm, dry area for about four days until the roots dry out a little.
Roots may be damaged when you remove the plant from the pot, and wounds to the plant are more likely to become infected with fungus or rot. The roots are just as vulnerable if you decide to prune them. Allowing the roots to dry can eliminate the risk of the roots becoming infected
Method 3 of 3: Placing the Cactus in a New Pot
Step 1. Use a pot one size larger
When choosing a new pot for your cactus, you should only choose a pot that is one size larger than your previous cactus pot. Larger pots can cause problems.
- If the pot is too large, the soil will end up holding more water. This water can linger around the roots and eventually cause the roots to rot
- Large pots should be avoided for varieties that are prone to root rot, such as Astrophytum, Ariocarpus, Lophophora, Aztecium, and Obregonia. However, this is less important for tougher species such as Cereus, Trichocereus, Hylocereus, Stenocereus, Myrtillocactus, and Opuntia.
Step 2. Put a little soil into the new pot
Place slightly rough potting soil at the bottom of the new pot. Use enough potting soil to keep the cactus planted to the same depth it was previously in the old pot.
You may also want to consider placing a layer of drainage material, such as gravel or clay pot shards, at the bottom of the pot before adding a layer of soil
Step 3. Wrap the newspaper to wrap the cactus
If you don't have the newspaper that was previously used when removing the cactus, prepare another newspaper wrap by stacking several layers of newspaper on top of each other and folding them in thirds. Wrap this newspaper around the cactus body.
- Make sure that you hold the cactus well through the newspaper.
- You should also wear your thick leather gloves during this process.
- If you don't have old newspapers, old, clean barbecue tongs will work as well.
Step 4. Hold the cactus in the center of the pot
Carefully pick up the cactus using newspaper and place it in the center of the new pot. Place in or above soil in pots.
Do not press the cactus into the soil. It can cause severe damage to the roots. You must carefully fill the roots with soil in order to secure them without causing any damage
Step 5. Add soil around the cactus
Carefully fill the space around your cactus with a coarser potting mix. Pour as much as needed to hold the cactus in the center of the pot without pressing the soil.
- When it's about half full, gently pat the sides of the pot. This will gently push the soil into the root mass. Repeat this step again after all the sides are completely filled.
- At this point, you should also make sure that the cactus is neither too deep nor too high. Carefully adjust the position of the cactus in the pot as necessary so that the green parts are above the soil while the brown roots remain below the soil.
Step 6. Consider adding compost and gravel
While not essential, a layer of compost can help maintain proper soil acidity and a layer of gravel or sand can improve drainage.
- The compost should be slightly acidic, with a pH between 4 and 5.5. Mix the compost into the soil along the sides of the pot.
- Simply spread a thin layer of gravel on the surface of the soil, scattering the gravel around the base of the cactus.
Step 7. Give the cactus additional recovery time
For tougher species, wait a few days to a week before watering your cactus so it can continue to dry and recover. For species prone to root rot, wait two to three weeks before watering.
